Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
spi: sh-msiof: Simplify BRG's Division Ratio
As FIELD_PREP() masks the value to be stored in the field, the Baud Rate
Generator's Division Ratio handling can be simplified from a look-up
table to a single subtraction.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/e736221942b0381fb53dc64109a1389f7ec5f44a.1747401908.git.geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
authored by
Geert Uytterhoeven
and committed by
Mark Brown
39d0856f
5b91dc7e
+2
-12
+2
-12
drivers/spi/spi-sh-msiof.c
+2
-12
drivers/spi/spi-sh-msiof.c
···
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/* SITSCR and SIRSCR */
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#define SISCR_BRPS GENMASK(12, 8) /* Prescaler Setting (1-32) */
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#define SISCR_BRDV GENMASK(2, 0) /* Baud Rate Generator's Division Ratio */
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#define SISCR_BRDV_DIV_2 0U
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#define SISCR_BRDV_DIV_4 1U
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-
#define SISCR_BRDV_DIV_8 2U
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-
#define SISCR_BRDV_DIV_16 3U
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#define SISCR_BRDV_DIV_32 4U
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#define SISCR_BRDV_DIV_1 7U
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/* SICTR */
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#define SICTR_TSCKIZ GENMASK(31, 30) /* Transmit Clock I/O Polarity Select */
···
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100);
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}
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static const u32 sh_msiof_spi_div_array[] = {
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SISCR_BRDV_DIV_1, SISCR_BRDV_DIV_2, SISCR_BRDV_DIV_4,
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SISCR_BRDV_DIV_8, SISCR_BRDV_DIV_16, SISCR_BRDV_DIV_32,
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};
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static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
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struct spi_transfer *t)
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{
···
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t->effective_speed_hz = parent_rate / (brps << div_pow);
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scr = FIELD_PREP(SISCR_BRDV, sh_msiof_spi_div_array[div_pow]) |
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/* div_pow == 0 maps to SISCR_BRDV_DIV_1 == all ones */
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scr = FIELD_PREP(SISCR_BRDV, div_pow - 1) |
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FIELD_PREP(SISCR_BRPS, brps - 1);
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sh_msiof_write(p, SITSCR, scr);
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if (!(p->ctlr->flags & SPI_CONTROLLER_MUST_TX))